Thick slices of fresh artichokes combine with fingerling potatoes, mushrooms, tangerines and pine nuts in this hearty winter salad. With a loaf of crusty bread it's satisfying enough for a meal.
Tangerines may seem unexpected, but they share the same harvest season as artichokes, and their tangy sweetness adds a perfect balance to the salad. Frisée or curly endive are ideal greens here because they stand up well to the warm dressing, but romaine or arugula will also work. If wild mushrooms are available, by all means use these instead of crimini for a distinctive earthy flavor.
Cut one of the lemons in half and squeeze the juice into a bowl of cold water, adding the lemon halves. Set aside.
Cut off and discard the bottom 1/2 inch of one artichoke stem. Peel the remaining stem, still attached, with a vegetable parer. Bend back the outer leaves at the base of the artichoke, and when the leaves snap, pull down sharply to remove the tough skin. Continue in a circular fashion around the artichoke, removing the bottom 2 or 3 layers of leaves. Cut off the top of the artichoke at a level even with the artichoke bottom and discard the leaves. Scrape out the small pointed leaves and hairy choke and discard. Drop the artichoke bottom in the bowl of lemon-acidulated water, acidulated with lemon juice to keep the artichoke from turning brown. Prepare the remaining artichoke in the same manner.
Steam the artichoke bottoms until just tender when pierced with a sharp knife or skewer, 10 to 15 minutes, depending on the size of your vegetables. Remove the artichokes with tongs and set them upside down on a wire rack to drain and cool. Cut the artichoke bottoms into thick (1/4-inch) slices and set aside at room temperature.
Cut the potatoes into thick (1/4-inch) slices. Arrange the frisée on a large shallow platter.
Place half of the olive oil in a large skillet and heat over high heat. Add the mushrooms and cook, stirring frequently, until lightly browned, about 5 minutes. Transfer the mushrooms to a plate and keep warm. Add the remaining olive oil to the skillet and add the artichoke and potato slices. Cook over high heat, turning the vegetables at least once so they brown on both sides. Transfer the mixture to the plate with the mushrooms. Turn off the heat under the skillet and add the juice of the remaining lemon and the walnut oil. Season the dressing with salt and pepper to taste. Arrange the warm vegetables over the frisée, and drizzle the dressing mixture from the pan over the greens. Garnish the salad with the tangerine segments and pine nuts, and serve immediately.